At high rotation speed of an aircraft engine in working, the dynamic properties of the aircraft engine directly influence the engine performance. According to statistics, more than 70% of aircraft engine failures are related to vibration. Severe vibration may cause great influence on the performance of the aircraft engine and even cause flight accidents, causing casualties and great economic losses. Therefore, it is urgent to solve the problem that the high-speed vibration amplitude of the aircraft engine during assembly is out of tolerance.
Suzhou Dongling Vibration Test Instrument Co., Ltd. invented an aircraft engine vibration control experiment platform which comprises an experiment platform base, an aircraft engine body, a driving system, a measurement and control system and a safety protection device, wherein a first driving motor of the driving system transmits power to a low-pressure rotor system of the aircraft engine body through a first coupler; a second driving motor transmits power to a high-pressure rotor system of the aircraft engine body through a second coupler and an accessory drive system of the aircraft engine body; a motor output shaft, the low-pressure rotor system and the high-pressure rotor system are provided with capacitive displacement sensors; and a two-stage casing, a three-stage casing, a six-stage casing, a combustor casing and a high-pressure turbine casing corresponding to five support bearings of the aircraft engine are provided with three-way vibration acceleration sensors. The experiment platform can be used for testing and analyzing multi-factor coupled vibration problems of the aircraft engine, and is widely applicable to the study of vibration properties and vibration control strategies of a dual-rotor system of the aircraft engine. The experiment platform has the defect that it does not comprehensively consider various key index factors of the aircraft engine to obtain a global optimal scheme.
The Northwestern Polytechnical University provided a method for improving vibration monitoring accuracy of multi-rotor aircraft engines. The method adopts the process of dynamically optimizing the sampling rate and sampling number to simultaneously avoid ‘spectral leakage’ at the fundamental frequency of each rotor and improve the amplitude value testing accuracy, thereby achieving engine failure diagnosis and providing a technical basis for on-site dynamic balance. The method has the defects that it does not fully consider the actual structure of the engine and the specific geometrical parameter values of the engine and does not accurately calculate the vibration conditions and the high-speed response properties of the aircraft engine through kinetic equations.
The above methods both have the following problems: only single objective optimization of the coaxiality is performed solely, the established coaxiality model does not consider the rotation errors around the X-axis and the Y-axis and does not consider the unbalance parameter and the rigidity parameter, and a comprehensive measuring model of coaxiality, amount of unbalance, rigidity and high-speed vibration response is not established, so distribution of coaxiality, amount of unbalance, rigidity and high-speed vibration response of multiple stages of rotor/stator of the aircraft engine cannot be realized.